const InitFFCodecReq = 0;
const CloseFFDecodeReq = 1;
const StartDecodeReq = 2;
const AudioPCMFrameRsp = 3;
const VideoRGBFrameRsp = 4;
const OnMessageEvent = 5;
const StartDecodeEndRsp = 6;
const InitFFCodecRsp = 7;
const MediaInfoRsp = 8;
const StopDecodeReq = 9;
const StopDecodeRsp = 10;
